Hey Andrew thanks for reporting this. Would you mind messaging me your options.txt file if this occurs again?

Sure thing; I can guarantee that it will crash tomorrow, if I try to load it.

Options attached; also the MS code that pops up, below:

Problem signature:
Problem Event Name: APPCRASH
Application Name: Foldit.exe
Application Version: 0.0.0.0
Application Timestamp: 50d112ec
Fault Module Name: game_library.dll
Fault Module Version: 0.0.0.0
Fault Module Timestamp: 525c907e
Exception Code: c0000005
Exception Offset: 014624bb
OS Version: 6.1.7601.2.1.0.256.4
Locale ID: 1033
Additional Information 1: 0a9e
Additional Information 2: 0a9e372d3b4ad19135b953a78882e789
Additional Information 3: 0a9e
Additional Information 4: 0a9e372d3b4ad19135b953a78882e789

Identical issue for 810.

Thank you. The issue here is when you exit a puzzle with Show Expected Residue Burials selected and displaying more than 3 residue burials, continuing into that puzzle will cause a crash. I've updated our database for this issue. In the meantime however the work around is to un-select that option when exiting/saving.

If I got in there by using the Tutorials, though, I can't change my options permanently... Should I enter into one of the beginner, non-credit puzzles in order to permanently change my options, or should I manually change the .txt file?

Manually changing the .txt file is the easiest way to resolve it.